This invention relates to an ink drop printing system which is configured for use as part of a duplicator. Such a duplicator may include an automatic document feeder for feeding original documents to be duplicated, a scanner for scanning documents which are so fed, and a storage device such as a magnetic disk for storing the information which is so scanned. Such a feeding, scanning and storage arrangement may be housed within a single cabinet.
In order to provide high quality printed copies of the original documents, it is necessary to read the stored information from memory and to use that information for controlling some type of dot matrix printer. Ink jet printers are generally suitable for such purposes, but prior art devices for the most part have not been suitable for utilization in a duplicator environment. Examples of typical prior art devices are shown in MacIlvaine U.S. Pat. No. 3,911,818 (forms printer), VanHook U.S. Pat. No. 4,009,332 (copier), Sweet U.S. Pat. No. 3,596,275 (oscillograph), Duffield U.S. Pat. No. 3,787,881 (bar code printer), Carmicheal et al U.S. Pat. No. 3,992,713 (word processor) and Bok et al U.S. Pat. No. 4,283,731 (address printer). Generally speaking, a suitable duplicator should be compact in design, capable of working from a plurality of paper supplies, and possess a relatively unique combination of speed and resolution capabilities; typically a speed of about 120 copies per minute and a resolution of about 350 lines per inch. The above-mentioned ink jet printers do not have such characteristics.
One example of ink jet printing in a duplicator environment is shown in Paranjpe et al U.S. Pat. No. 4,259,696. In a duplicator of that particular type, it is necessary to supply sheets of paper to a printing drum at very high speed and to oscillate the printing head back and forth while the sheets spin around the drum. Such operations require devices which are expensive to produce and prone to mechanical failure.